| Name | Meanings | Gender | Origin |
|---|---|---|---|
| Obelia | pillar of strength | Girl | Greek |
| Oceana | Ocean | Girl | Greek |
| Odele | Wealthy | Girl | Greek |
| Odessa | a long journey | Girl | Greek |
| Olivia | olive tree | Girl | Greek |
| Olympia | Mountain of the Gods | Girl | Greek |
| Ophelia | serpent | Girl | Greek |
| Oria | From the Orient | Girl | Greek |
| Oriana | Golden One | Girl | Greek |
| Orion | son of fire, the hunter | Boy | Greek |
| Otis | One Who Hears Well | Boy | Greek |
| Hawaiian |
| Vietnamese |
| Ghanaian |
| Anglo-Saxon |
| Sanskrit |